The present invention relates to a load application mechanism of the Rockwell hardness tester. More in particular, it relates to a load application mechanism that permits smooth transfer of load from a load application level to an indenter shaft without difficulty.
Conventionally, the load application mechanism of such type has been popularly used, in which transfer of load from the load application level to the spring support cylinder on the indenter shaft is conducted through a monobloc load transfer member with parallel knife edges formed along its upper and lower ends. With this type of conventional load application mechanism, it is difficult to work the knife edges and their receivers with a high degree of accuracy. Consequently, error may arise in load or displacement of the pressure shaft, under the effect of an eccentric load imposed on the indenter shaft.
Then it becomes conceivable to apply to the load application mechanism of a Rockwell hardness tester, an idea of interposing a load transfer member having an upper and a lower knife edge and a universal joint between the load application level and the indenter shaft, as described in the Official Patent Gazette No. 39-16495. However, this type of system also involves several problems. It still requires high-precision work to insure the parallelism of the knife edges formed along the upper and lower ends of the load transfer member. The universal joint must be prepared with high accuracy, too.